Falling oxygen levels caused by global warming could be a greater threat to the survival of life on Earth than flooding, according to researchers from the University of Leicester in the UK.

The study has shown that an increase in the water temperature of the world's oceans of around six degrees Celsius - which some scientists predict could occur as soon as 2100 - could stop oxygen production by phytoplankton by disrupting the process of photosynthesis.

"Global warming has been a focus of attention of science and politics for about two decades now," Sergei Petrovskii, Professor at Leicester's Department of Mathematics, said.

"A lot has been said about its expected disastrous consequences; perhaps the most notorious is the global flooding that may result from melting of Antarctic ice if the warming exceeds a few degrees compared to the pre-industrial level," said Petrovskii.

The research was published in the journal Bulletin of Mathematical Biology.